Identifying Modeled Ship Noise Hotspots for Marine Mammals of Canada's Pacific Region

Abstract

The inshore, continental shelf waters of British Columbia (BC), Canada are busy with ship traffic. South coast waters are heavily trafficked by ships using the ports of Vancouver and Seattle. North coast waters are less busy, but expected to get busier based on proposals for container port and liquefied natural gas development and expansion. Abundance estimates and density surface maps are available for 10 commonly seen marine mammals, including northern resident killer whales, fin whales, humpback whales, and other species with at-risk status under Canadian legislation. Ship noise is the dominant anthropogenic contributor to the marine soundscape of BC, and it is chronic. Underwater noise is now being considered in habitat quality assessments in some countries and in marine spatial planning. We modeled the propagation of underwater noise from ships and weighted the received levels by species-specific audiograms. We overlaid the audiogram-weighted maps of ship audibility with animal density maps. The result is a series of so-called “hotspot” maps of ship noise for all 10 marine mammal species, based on cumulative ship noise energy and average distribution in the boreal summer. South coast waters (Juan de Fuca and Haro Straits) are hotspots for all species that use the area, irrespective of their hearing sensitivity, simply due to ubiquitous ship traffic. Secondary hotspots were found on the central and north coasts (Johnstone Strait and the region around Prince Rupert). These maps can identify where anthropogenic noise is predicted to have above-average impact on species-specific habitat, and where mitigation measures may be most effective. This approach can guide effective mitigation without requiring fleet-wide modification in sites where no animals are present or where the area is used by species that are relatively insensitive to ship noise.

Assessing the risk of chronic shipping noise to baleen whales off Southern California, USA

“…It could also be expanded beyond the single frequencies we selected to capture the variable contributions from shipping to noise using one-third octave bands or audiogram weighting (e.g. the approach developed by Erbe et al 2014). …”

“…These noise and risk characterizations allow managers and stakeholders to identify areas where chronic noise may impact the acoustic environment of these 3 species in Southern California waters. Specifically, our assessment identified hot spots of noise in species habitats, similar to Erbe et al (2014), and areas within species habitats that are quiet, similar to Williams et al (2015).…”

“…For example, Erbe et al (2012) mapped cumulative underwater acoustic energy from shipping using a simple sound transmission model and Automatic Identification System (AIS) data. Erbe et al (2014) combined these data with distribution maps for 10 species (including dolphins, porpoises, baleen whales, and pinnipeds) using audiogram weighting across a range of fre-quencies to identify species-specific hotspots of ship noise. Williams et al (2015) used the same data and approach, but identified important species habitats that occur in areas with little noise.…”

The Grand Challenges in Researching Marine Noise Pollution from Vessels: A Horizon Scan for 2017

“…Perhaps unsurprisingly, we found them to be largely in agreement with one another once we considered the content of the articles, the workshop discussion, and rationale behind scoring of questions. Hooker and Gerber, 2004;Firestone and Jarvis, 2007;Haren, 2007;Weilgart, 2007;Tyack, 2008;Codarin et al, 2009;Hatch and Fristrup, 2009;Wright et al, 2011;Simmonds et al, 2014;Williams et al, 2014a;Bas et al, 2015;Williams et al, 2015a;Erbe et al, 2016b;Hatch et al, 2016;Pine et al, 2016 2 13 10 4 Lesage et al, 1999;Buckstaff, 2004;Wright et al, 2007;Hatch and Fristrup, 2009;Jensen et al, 2009;Ellison et al, 2011;Merchant et al, 2012b;Williams et al, 2014a;Maccarrone et al, 2015;Brooker and Humphrey, 2016;Erbe et al, 2016b;Farcas et al, 2016;Prins et al, 20163 13 11 3 Nowacek et al, 2001Johnson and Tyack, 2003;Firestone and Jarvis, 2007;Horowitz and Jasny, 2007;Weilgart, 2007;Hatch and Fristrup, 2009;Holt et al, 2009;Wieland et al, 2010;Williams et al, 2014a;…”

Underwater Noise Modeling in Lithuanian Area of the Baltic Sea

“…Šiuo metu yra žinoma nemažai sudėtingų fizikinių povandeninio triukšmo modelių (Jensen et al 2011;Carey, Evans 2011;Etter 2012), tačiau supaprastintų priemonių, skirtų povandeniniam triukšmui modeliuoti bei aplinkos būklei vertinti, vis dar yra nedaug (Erbe et al 2012). Šiuo tikslu Klaipėdos universitete buvo pradėtas kurti supaprastintas povandeninio triukšmo modelis, kurį taikant galima prognozuoti laivų sukeliamo triukšmo lygius erdvėje, pasitelkiant jau turimą kitų šalių patirtį (Erbe et al 2014;Gervaise et al 2015;Simard et al 2016). Šio modelio programavimas buvo suskirstytas į 3 etapus: 1) programinio modulio, skirto automatinės identifikavimo sistemos (AIS) laivų registravimo duomenims apdoroti bei laivų triukšmo lygiams (GSL) tiriamoje vietovėje apskaičiuoti, sukūrimas; 2) modulio, skirto triukšmo lygių vidurkiams apskaičiuoti priklausomą triukšmo sklidimą, įtraukiant mažo gylio atkirtimo dažnio bei žemo dažnio korekcijas; 3) apskaičiavo triukšmo lygių vidurkius bei statistinius duomenis langeliuose bei erdvinį duomenų tinklelį toliau apdoroti (kartografuoti).…”